Unit Test failure: Non existent view: error0

I am writing a custom transformation snap to build a custom payload for one of our external systems. I have implemented the ErrorSchemaProvider interface and, following the patterns of the view names from the InputSchemaProvider and OutputSchemaProvider, I specified the view name as “error0”.

@Override
public void defineErrorSchema(final SchemaProvider provider) {
    provider.getSchemaBuilder("error0")
        .withChildSchema(provider.createSchema(SnapType.STRING, BAR_NUMBER))
        .withChildSchema(provider.createSchema(SnapType.STRING, ERROR_TYPE))
        .withChildSchema(provider.createSchema(SnapType.STRING, ERROR_MESSAGE))
        .build();
}

Unfortunately, this is causing the unit test to fail with the error: Non existent view: error0

@RunWith(SnapTestRunner.class)
public class AddAttorneyPayloadBuilderTest {

@TestFixture(snap = AddAttorneyPayloadBuilder.class,
    input = "data/add_attorney/input.json",
    errors = { "error0" },
    expectedOutputPath = "data/add_attorney/expected",
    expectedErrorPath = "data/two_inputs_two_outputs/expected")
public void addAttorney_WithValidData_BuildsXmlPayload() { }

}

I am clearly doing something stupid. Any pointers at what I need to do to fix the problem?

Thanks,
Robert